Ingham



D. D FROTHINGHAM AND. R. U. SAWYER.

' METHOD 0F COATING FABRICS. APPLICATION FILED FEB-18,1918.

2 SHEETSSHEET I- D. D. FROTHINGHAM AND R. U. SAWYER.

METHOD OFCOATING FABRiCS. APPLICATION FILED FEB. 18', 1918.

Patented Sept. 23, .1919.

2 SHEETS-SHEET 2.

DANIEL D. FROTHINGHAM, OF

SALEM, AND RALPH U. SAWYER, F WINCHESTER,

MASSACHUSETTS, ASSIGNORS T0 SAWYER PRODUCTS COMPANY, OF WATER- TOWN, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

METHOD OF COATING FABRICS.

Specification of Letters Patent. Patented Sept. 23, 1919.

, Application filed February 18, 1918. Serial No. 217,567.

. To all whom it may concern:

Be it known that we, DANIEL D. Fno'rn- INGHAM and RALPH U. SAWYER, citizens of the United States, residing at Salem and Winchester, respectively, in the counties of Essex and Middlesex, respectively, and State of Massachusetts, have invented certain new and useful Improvements in Methods of Coating Fabrics; and We do hereby declare the following to Joe a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to a method of coating fabrics. The object of the invention is to reduce the cost of coating fabrics and to improve the, product. To these ends the invention consists in the method hereinafter described and particularly defined in the claims.

In the accompanying drawings illustrating diagrammatically .a machine by which this method may be practised, Figure 1 is a sectional elevation of the machine; Fig. 2 is a skeleton plan of the same; and Fig. 3 is an enlarged detail illustrating the action of the presser on the coating material.

From the roll 1 of cloth the strip 2 is passed around a guide roll 3 and thence over a tension roller 4 around a guide roll 5, over a lateral stretching roller 6, under a presser 7 thence over a tension roller 8, from which it passes into the oven 9 and thence over guide rolls toa drying room. The coating material is supplied under pressure (produced by compressed air) through the pipe 10 to the angle between the cloth and the presser 7, diverging nozzle cocks 11 being employed to distribute the coating on the cloth. The coating material is in a stiff viscous condition, and the tension to which the cloth is subjected as it passes under the presser 7 causes the coating material to be forced with great pressure into the cloth. It will be observed-by reference to Fig. 3 that the viscosity of the coating material '12 is such that as the cloth approaches the presser it deflects the cloth from its natural course, owing to the resistance to distortion of form due to the viscosity of the coating material in the angle between the cloth and the presser. The coating material is therefore forced into the interstices of the cloth with great pressure, and penetrates such interstices and forms tentacle-like integral pro ect1ons on the coating which bind and securely hold the coating to the cloth, but,

the reference character 13, Where the roll of coating material first engages the cloth, to a point, indicated by the reference character 14;, where the cloth leaves the presser. The pressure, therefore, by which the coating is forcedinto and spread out upon the surface of the cloth, is long continued and extended over a considerable length of the cloth. It will be observed that the coatingis applied to the concave side of the cloth so that the tension of the cloth causes it to exert a pressure against the presser throughout the whole duration of its passage by the presser and the viscous coating material over the whole distance from the point 13 to the point 14:.

Heretofore the coating material has been applied in a number of layers in order to build up the requisite thickness of coating, and the coating material has been in .a relatively fluid state, requiring a comparatively rapid movement of the cloth under the coating material in order to prevent the latter from penetrating through the cloth. According to the present invention, the coating is so stifi' that it cannot penetrate through the cloth even under great pressure long applied, ant the cloth, therefore, progresses through the machine at a slow rate of speed. This contributes to the firm union. of the coating With the cloth.

The presser is distinguished from prior doctors or knives by reason of the considerable area throughout which it acts upon the ing material upon the cloth and to accom- I plish its firm union therewith. It is preferred, however, to use a presser about four and a half inches thick so that a large area 7 Wood alcohol 90 oz. Acetone 36 oz. Amylaeetate 12 oz. Scrap celluloid 54-60 oz. Castor oil 72 oz. Soluble or spirit negrocin 1} oz.

This coating material is prepared by mixing the solvents, viz., the wood alcohol, acetone and amylacetate, and the soluble or spirit negrocin, in a mixer, and then the comminuted scrap celluloid, such as cleaned moving-picture films, or other similar base, such as cellulose acetate, is introduced into the mixer and the mixing process is continued until the celluloid is dissolved and the material rendered homogeneous, after which the castor oil is stirred or mixed in. The resulting coating material is a stiff viscous mass which, it will be observed, contains a comparatively small amount of solvent, and is therefore a much cheaper coating material than one in which a larger quantity of solvent is employed. The amount of solvent necessary for coating a given length of cloth is about the same as that heretofore required for considerably less than half such yardage; for example, with this coating 7-1; yards of goods may be coated as agalnst 24; yards using the usual amount of solvent. This effects, therefore, a material savlng 1n the cost of the coating. I

If a coating having a high gloss 1s demanded, the amount of acetone will be decreased and the amount of amylacetate will be increased, thus by changing the formula so that the acetone will be 26 oz. and the amylacetate 22 oz., a coating having a high gloss will be produced. be employed if desired, and in case it would not be objectionable for the coating to display a bloom the amylacetate may be entirely omitted. By increasing the castor Oll content the flexibility of the coating may be increased. This non-drying oil preserves the flexibility of the coating, and the amount stated in the formula is sufficient to secure a coatin of 20 oz. to the square yard of such flexibi ity that when bent upon itself it W111 not break, even after repeated bending, and at so low a temperature as zero F. It is conceivable, ofcourse, that it might be desiralble under certain circumstances to increase the flexibility, and under these condi- Other solvents may tions an increase in the castor oil content would be indicated. The coating of the formula is such that it may be applied to the coating maybe applied to cloth by a single passage through the machine, thereby producing an integral unitary coating with the saving incident to passing the material through the machine once instead of the many times usually practised, and which, in the case of a- 20 oz. coating, would be, according to existing practice, from four to twelve times. One of the features of the method resides in the use of a non-pigmentous coloring matter. The introduction of bone black, coach black, ivory black or other pigment into the coating material renders it much less flexible than otherwise, and quite friable in some cases at low temperatures, and one of the important features of the invention resides in the entire elimination of the use of solid pigment.

A feature of importance in the invention has to do with the appearance of the coating after it has been applied. Hereto-fore, after the first layer was applied to the cloth, all subsequent layers have displayed pin-holes which detract from the appearance of the material, whereas in cloth coated according to the present method no pin-holes are formed. The pin-hole problem in the coat ing of cloths or other fabrics has been one to which much attention has been directed, but so far without practical elimination. The reason for the pin-holes is not known. Many theories have been advanced to explain their existence, but none has so far been accepted, and the fact that the present process entirely avoids the formation of pin-holes commends it highly.

It will be apparent to those skilled in the art that the present process will effect a saving of approximately 50% on the present cost of coating cloths practised by the manufacturers of coated cloths, imitation leather and the like. Not only is the coating, therefore, very much less expensive than the coating heretofore employed, but by reason of the avoidance of pin-holes the product is much to be preferred, in fact, so much to be preferred that it will command a higher price in the market than the existing coated fabrics. I

The fabric to be coated may be passed through the machine at a rate of speed of from 2 yards to the minute, which is the preferred rate of speed, to 10 yards to the minute. It is to be observed that with a given mixture or constitution of coating, and a given thickness of coating to be applied, when the speed of passage of the fabric through the machine is increased, the, pressure by which thecoating is applied to th fabric is also increased, in order to preserve the same thickness of coating. Furthermore, it is to be observed that by varying the speed or the tension on the fabric, or both, the thickness of the coating may be varied. Thus, other things standing fast, by increasing the speed, the thickness of the coating will be increased; by increasin the tension, the thickness of the coating will edecreased; and by increasing the speed and decreasing the tension, the coating may be maintained at the same thickness; but the tenacity of the cohesion between the coating and the cloth may be varied. The speed should not be increased so much as to deprive the coating of adequate fixation to the-fabric, nor

should the tension be decreased so much as of a presser, applyi to permit inequalitiesin the thickness of the coating.

The coated fabric and machine disclosed herein form the subject matter of copending applications filed b us on even date herewith and bearing erial Nos. 217,968and 217,969 respectively.

Having thus described the invention, what is claimed is 1. The method of coating fabrics which consists in applying a coating material of the nature described in a stiff viscous condition to the fabric to be coated by the exertion of long-continued rubbing pressure between the coating material and the fabric.

2. The method of coating fabrics which consists inapplying a single homogeneous coat of coating material of the nature described in a stiff viscous condition to the fabric to be coated by long-continued rubbin pressure between the coating material an the fabric.

3. The method of coating fabrics which consists in placing the fabric under tension, drawing the same around the convex surface a mass of coating material of the nature escribed in a stiff viscous condition to the presser side of the fabme to be rubbingly pressed against the con time to effect a strong vex surface of of the fabric.

4. The method of coating fabric which consists in applying to the surface of the fabric to be coated a mass of coating material in a stiff viscous condition and of such consistency that it will not flow through the interstices of the material to be coated, and causingpressure to be exerted between the coating material and the fabric for a considerable length of time so that the coating is first reduced to the desired thickness and thereafter subjected to continued rubbing pressure.

5. The method of coating fabrics which consists in preparing a coating material compounded of a small amount of solvent and a large amount of celluloid, and applying a single coat of such material in a stiff viscous condition on the fabric by reducing it under pressure on'the fabric to the desired thickness and maintaining the coatingapplying pressure for a sufiicient length of union between the the presser by the tension fabric and the coating.

6. The method of coating fabrics which consists inpassing a fabric around and in contact with a material portion of the convex surface of a presser and applying a mass of coating material in -a stifl viscous condition to the fabric in front of the presser so that as the fabric passes around the presser the mass'of coatin material is first'reduced to a predetermine thickness during the first period of contact therewith and is then subected to continued rubbing pressure to smooth the surface thereof and securely bond the same to the fabric. v T

7. The method of coating fabrics which consists in passing a fabric around and in contact with a material portion of the convex surface of a presser and applying a mass of coating material in a stiff viscous condition to the fabric in front of the presser so that as the fabric passes around the presser the coating is subjected to pressure after the desired amount has been applied to the fabric. 

